【摘要】 热应激是影响奶牛产奶性能的主要因素之一。本研究对河南省焦作市某牧场800头泌乳期奶牛在热应激期（8月份，THI≥68）和非热应激期（4月份，THI<68）的生产数据（包括产奶量、乳品质及繁殖指标）进行了比较，结果显示，热应激期比非热应激期日均产奶量下降2.95 kg(P<0.05)，乳蛋白率降低0.06个百分点（P<0.05），情期受胎率降低7.87个百分点（P<0.01）。结合文献分析，热应激可能通过抑制干物质采食量、扰乱能量分配、损害下丘脑-垂体-卵巢轴（HPO轴）功能及诱发氧化应激等多途径影响奶牛生产性能。更多还原

【Abstract】 Under significant cost pressures in the dairy industry, heat stress markedly impairs the production performance of lactating dairy cows. This study compared data from 800 cows on a farm in Jiaozuo, Henan Province, during heat stress(August, THI≥68) and non-heat stress(April, THI<68) periods. The results demonstrated that heat stress led to: a significant reduction in milk yield by 2.95 kg/d(P<0.05), a decrease in milk protein content by 0.06 percentage points(P<0.05), and a highly significant decline in conception rate by 7.87 percentage points(P<0.01). Mechanistic analysis, supported by existing literature, suggests that heat stress impairs production performance through multiple pathways: suppressing dry matter intake, disrupting energy partitioning, compromising hypothalamic-pituitary-ovarian(HPO) axis function, and inducing oxidative stress.更多还原